C - control: always include a control in your experiment, eg for the light intensity leaf experiment have an empty test tube with just some indicator in it...
O - organism: what organisms will be involved and what similarities do they need to have eg. same sex, age, health, ect
R - repetition: how many repeats do you do to make it more practical?
M - measurement: what do you plan to measure? eg growth length temperature weight size ect.
S - standard: what do you need to keep the same? eg time, diet, oxygen, light intensities pH ect